Implement a bluetooth picker dialog for Android

chrome/android/java/src/org/chromium/chrome/browser/ItemChooserDialog.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser;
 
 import android.app.Dialog;
 import android.content.Context;
+import android.content.DialogInterface;
 import android.graphics.Color;
 import android.graphics.drawable.ColorDrawable;
 import android.text.SpannableString;
 import android.text.method.LinkMovementMethod;
 import android.util.DisplayMetrics;
 import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
 import android.view.Window;
 import android.view.WindowManager;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
 import android.widget.Button;
 import android.widget.LinearLayout;
 import android.widget.ListView;
 import android.widget.ProgressBar;
 import android.widget.TextView;
 
 import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.chrome.R;
 import org.chromium.ui.base.DeviceFormFactor;
 import org.chromium.ui.widget.TextViewWithClickableSpans;
 
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 /**
  * A general-purpose dialog for presenting a list of things to pick from.
  */
 public class ItemChooserDialog {
     /**
      * An interface to implement to get a callback when something has been
      * selected.
      */
     public interface ItemSelectedCallback {
@@ skipping 24 matching lines @@
      */
     public static class ItemChooserLabels {
         // The title at the top of the dialog.
         public final SpannableString mTitle;
         // The message to show while results are trickling in.
         public final String mSearching;
         // The message to show when no results were produced.
         public final SpannableString mNoneFound;
         // A status message to show above the button row.
         public final SpannableString mStatus;
+        // An error state.
+        public final SpannableString mErrorMessage;
+        // A status message to go with the error state.
+        public final SpannableString mErrorStatus;
         // The label for the positive button (e.g. Select/Pair).
         public final String mPositiveButton;
 
         public ItemChooserLabels(SpannableString title, String searching, SpannableString noneFound,
-                SpannableString status, String positiveButton) {
+                SpannableString status, SpannableString errorMessage, SpannableString errorStatus,
+                String positiveButton) {
             mTitle = title;
             mSearching = searching;
             mNoneFound = noneFound;
             mStatus = status;
+            mErrorMessage = errorMessage;
+            mErrorStatus = errorStatus;
             mPositiveButton = positiveButton;
         }
     }
 
     /**
+     * The various states the dialog can represent.
+     */
+    private enum State {
+        STARTING,
+        PROGRESS_UPDATE_AVAILABLE,
+        SHOWING_ERROR,
+    }
+
+    /**
      * An adapter for keeping track of which items to show in the dialog.
      */
     private class ItemAdapter extends ArrayAdapter<ItemChooserRow>
             implements AdapterView.OnItemClickListener {
         private final LayoutInflater mInflater;
 
         // The background color of the highlighted item.
         private final int mBackgroundHighlightColor;
 
         // The color of the non-highlighted text.
         private final int mDefaultTextColor;
 
         // The zero-based index of the item currently selected in the dialog,
         // or -1 (INVALID_POSITION) if nothing is selected.
         private int mSelectedItem = ListView.INVALID_POSITION;
 
+        // A set of keys that are marked as disabled in the dialog.
+        private Set<String> mDisabledEntries = new HashSet<String>();
+
         public ItemAdapter(Context context, int resource) {
             super(context, resource);
 
             mInflater = LayoutInflater.from(context);
 
             mBackgroundHighlightColor = ApiCompatibilityUtils.getColor(getContext().getResources(),
                     R.color.light_active_color);
             mDefaultTextColor = ApiCompatibilityUtils.getColor(getContext().getResources(),
                     R.color.default_text_color);
         }
 
         @Override
         public void clear() {
             mSelectedItem = ListView.INVALID_POSITION;
             mConfirmButton.setEnabled(false);
             super.clear();
         }
 
         /**
          * Returns the key of the currently selected item or blank if nothing is
          * selected.
          */
         public String getSelectedItemKey() {
             ItemChooserRow row = getItem(mSelectedItem);
             if (row == null) return "";
             return row.mKey;
         }
 
+        /**
+         * Sets whether the itam is enabled. Disabled items are grayed out.
+         * @param id The id of the item to affect.
+         * @param enabled Whether the item should be enabled or not.
+         */
+        public void setEnabled(String id, boolean enabled) {
+            if (enabled) {
+                mDisabledEntries.remove(id);
+            } else {
+                mDisabledEntries.add(id);
+            }
+            notifyDataSetChanged();
+        }
+
+        @Override
+        public boolean isEnabled(int position) {
+            ItemChooserRow item = getItem(position);
+            return !mDisabledEntries.contains(item.mKey);
+        }
+
         @Override
         public int getViewTypeCount() {
             return 1;
         }
 
         @Override
         public long getItemId(int position) {
             return position;
         }
 
         @Override
         public View getView(int position, View convertView, ViewGroup parent) {
             TextView view;
             if (convertView instanceof TextView) {
                 view = (TextView) convertView;
             } else {
                 view = (TextView) mInflater.inflate(
                         R.layout.item_chooser_dialog_row, parent, false);
             }
 
             // Set highlighting for currently selected item.
             if (position == mSelectedItem) {
                 view.setBackgroundColor(mBackgroundHighlightColor);
                 view.setTextColor(Color.WHITE);
             } else {
                 view.setBackground(null);
-                view.setTextColor(mDefaultTextColor);
+                if (!isEnabled(position)) {
+                    view.setTextColor(getContext().getResources().getColor(
+                            R.color.primary_text_disabled_material_light));
+                } else {
+                    view.setTextColor(mDefaultTextColor);
+                }
             }
 
             ItemChooserRow item = getItem(position);
             view.setText(item.mDescription);
             return view;
         }
 
         @Override
         public void onItemClick(AdapterView<?> adapter, View view, int position, long id) {
             mSelectedItem = position;
             mConfirmButton.setEnabled(true);
             mItemAdapter.notifyDataSetChanged();
         }
     }
 
     private Context mContext;
 
     // The dialog this class encapsulates.
     private Dialog mDialog;
 
     // The callback to notify when the user selected an item.
     private ItemSelectedCallback mItemSelectedCallback;
 
     // Individual UI elements.
     private TextViewWithClickableSpans mTitle;
-    private TextViewWithClickableSpans mNotFoundMessage;
+    private TextViewWithClickableSpans mEmptyMessage;
     private ProgressBar mProgressBar;
     private ListView mListView;
     private TextView mStatus;
     private Button mConfirmButton;
 
     // The labels to display in the dialog.
     private ItemChooserLabels mLabels;
 
     // The adapter containing the items to show in the dialog.
     private ItemAdapter mItemAdapter;
@@ skipping 19 matching lines @@
         mLabels = labels;
 
         LinearLayout dialogContainer = (LinearLayout) LayoutInflater.from(
                 mContext).inflate(R.layout.item_chooser_dialog, null);
 
         mListView = (ListView) dialogContainer.findViewById(R.id.items);
         mProgressBar = (ProgressBar) dialogContainer.findViewById(R.id.progress);
         mStatus = (TextView) dialogContainer.findViewById(R.id.status);
         mTitle = (TextViewWithClickableSpans) dialogContainer.findViewById(
                 R.id.dialog_title);
-        mNotFoundMessage =
-                (TextViewWithClickableSpans) dialogContainer.findViewById(
-                        R.id.not_found_message);
+        mEmptyMessage =
+                (TextViewWithClickableSpans) dialogContainer.findViewById(R.id.not_found_message);
 
         mTitle.setText(labels.mTitle);
         mTitle.setMovementMethod(LinkMovementMethod.getInstance());
 
-        mNotFoundMessage.setText(labels.mNoneFound);
-        mNotFoundMessage.setMovementMethod(LinkMovementMethod.getInstance());
-
-        mStatus.setText(labels.mSearching);
+        mEmptyMessage.setMovementMethod(LinkMovementMethod.getInstance());
         mStatus.setMovementMethod(LinkMovementMethod.getInstance());
 
         mConfirmButton = (Button) dialogContainer.findViewById(R.id.positive);
         mConfirmButton.setText(labels.mPositiveButton);
         mConfirmButton.setEnabled(false);
         mConfirmButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 mItemSelectedCallback.onItemSelected(
                         mItemAdapter.getSelectedItemKey());
+                mDialog.setOnDismissListener(null);
                 mDialog.dismiss();
             }
         });
 
         mItemAdapter = new ItemAdapter(mContext, R.layout.item_chooser_dialog_row);
         mListView.setAdapter(mItemAdapter);
-        mListView.setEmptyView(mNotFoundMessage);
-        mNotFoundMessage.setVisibility(View.GONE);
+        mListView.setEmptyView(mEmptyMessage);
         mListView.setOnItemClickListener(mItemAdapter);
         mListView.setDivider(null);
+        setState(State.STARTING);
 
         // The list is the main element in the dialog and it should grow and
         // shrink according to the size of the screen available (clamped to a
         // min and a max).
         View listViewContainer = dialogContainer.findViewById(R.id.container);
         DisplayMetrics metrics = new DisplayMetrics();
         WindowManager manager = (WindowManager) mContext.getSystemService(
                 Context.WINDOW_SERVICE);
         manager.getDefaultDisplay().getMetrics(metrics);
 
         float density = context.getResources().getDisplayMetrics().density;
         int height = (int) (metrics.heightPixels * LISTVIEW_HEIGHT_PERCENT);
         height = Math.min(height, Math.round(MAX_HEIGHT_DP * density));
         height = Math.max(height, Math.round(MIN_HEIGHT_DP * density));
         listViewContainer.setLayoutParams(
                 new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, height));
 
         showDialogForView(dialogContainer);
     }
 
     private void showDialogForView(View view) {
         mDialog = new Dialog(mContext);
         mDialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
         mDialog.addContentView(view,
                 new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
                                               LinearLayout.LayoutParams.MATCH_PARENT));
+        mDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
+            @Override
+            public void onDismiss(DialogInterface dialog) {
+                mItemSelectedCallback.onItemSelected("");
+            }
+        });
 
         Window window = mDialog.getWindow();
         if (!DeviceFormFactor.isTablet(mContext)) {
             // On smaller screens, make the dialog fill the width of the screen,
             // and appear at the top.
             window.setBackgroundDrawable(new ColorDrawable(Color.WHITE));
             window.setGravity(Gravity.TOP);
             window.setLayout(ViewGroup.LayoutParams.MATCH_PARENT,
                              ViewGroup.LayoutParams.WRAP_CONTENT);
         }
 
         mDialog.show();
     }
 
+    public void dismiss() {
+        mDialog.dismiss();
+    }
+
     /**
      * Add items to show in the dialog.
      *
      * @param list The list of items to show. This function can be called
      * multiple times to add more items and new items will be appended to
      * the end of the list. An empty list should be used if there are no
      * items to show.
      */
     public void showList(List<ItemChooserRow> list) {
         mProgressBar.setVisibility(View.GONE);
-        mStatus.setText(mLabels.mStatus);
 
-        if (list.isEmpty()) {
-            boolean showEmptyMessage = mItemAdapter.isEmpty();
-            mNotFoundMessage.setVisibility(
-                    showEmptyMessage ? View.VISIBLE : View.GONE);
-            mListView.setVisibility(showEmptyMessage ? View.GONE : View.VISIBLE);
-        } else {
-            mListView.setVisibility(View.VISIBLE);
+        if (!list.isEmpty()) {
             mItemAdapter.addAll(list);
         }
+        setState(State.PROGRESS_UPDATE_AVAILABLE);
     }
 
     /**
+     * Sets whether the item is enabled.
+     * @param id The id of the item to affect.
+     * @param enabled Whether the item should be enabled or not.
+     */
+    public void setEnabled(String id, boolean enabled) {
+        mItemAdapter.setEnabled(id, enabled);
+    }
+
+    /**
      * Clear all items from the dialog.
      */
     public void clear() {
         mItemAdapter.clear();
+        setState(State.STARTING);
+    }
+
+    /**
+     * Set the error state for the dialog.
+     */
+    public void setErrorState() {
+        setState(State.SHOWING_ERROR);
+    }
+
+    private void setState(State state) {
+        switch (state) {
+            case STARTING:
+                mStatus.setText(mLabels.mSearching);
+                mListView.setVisibility(View.GONE);
+                mProgressBar.setVisibility(View.VISIBLE);
+                break;
+            case SHOWING_ERROR:
+                mProgressBar.setVisibility(View.GONE);
+                mEmptyMessage.setText(mLabels.mErrorMessage);
+                mStatus.setText(mLabels.mErrorStatus);
+                break;
+            case PROGRESS_UPDATE_AVAILABLE:
+                mStatus.setText(mLabels.mStatus);
+                mProgressBar.setVisibility(View.GONE);
+                mListView.setVisibility(View.VISIBLE);
+
+                boolean showEmptyMessage = mItemAdapter.isEmpty();
+                mEmptyMessage.setText(mLabels.mNoneFound);
+                mEmptyMessage.setVisibility(showEmptyMessage ? View.VISIBLE : View.GONE);
+                break;
+        }
     }
 }